/*
 * contrib/intarray/_int_op.c
 */
#include "postgres.h"


#include "_int.h"

PG_MODULE_MAGIC;

PG_FUNCTION_INFO_V1(_int_different);
PG_FUNCTION_INFO_V1(_int_same);
PG_FUNCTION_INFO_V1(_int_contains);
PG_FUNCTION_INFO_V1(_int_contained);
PG_FUNCTION_INFO_V1(_int_overlap);
PG_FUNCTION_INFO_V1(_int_union);
PG_FUNCTION_INFO_V1(_int_inter);

Datum
_int_contained(PG_FUNCTION_ARGS)
{
    /* just reverse the operands and call _int_contains */
    return DirectFunctionCall2(_int_contains,
                               PG_GETARG_DATUM(1),
                               PG_GETARG_DATUM(0));
}

Datum
_int_contains(PG_FUNCTION_ARGS)
{
    /* Force copy so we can modify the arrays in-place */
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    ArrayType  *b = PG_GETARG_ARRAYTYPE_P_COPY(1);
    bool        res;

    CHECKARRVALID(a);
    CHECKARRVALID(b);
    PREPAREARR(a);
    PREPAREARR(b);
    res = inner_int_contains(a, b);
    pfree(a);
    pfree(b);
    PG_RETURN_BOOL(res);
}

Datum
_int_different(PG_FUNCTION_ARGS)
{
    PG_RETURN_BOOL(!DatumGetBool(
                                 DirectFunctionCall2(
                                                     _int_same,
                                                     PointerGetDatum(PG_GETARG_POINTER(0)),
                                                     PointerGetDatum(PG_GETARG_POINTER(1))
                                                     )
                                 ));
}

Datum
_int_same(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    ArrayType  *b = PG_GETARG_ARRAYTYPE_P_COPY(1);
    int            na,
                nb;
    int            n;
    int           *da,
               *db;
    bool        result;

    CHECKARRVALID(a);
    CHECKARRVALID(b);
    na = ARRNELEMS(a);
    nb = ARRNELEMS(b);
    da = ARRPTR(a);
    db = ARRPTR(b);

    result = FALSE;

    if (na == nb)
    {
        SORT(a);
        SORT(b);
        result = TRUE;

        for (n = 0; n < na; n++)
        {
            if (da[n] != db[n])
            {
                result = FALSE;
                break;
            }
        }
    }

    pfree(a);
    pfree(b);

    PG_RETURN_BOOL(result);
}

/*    _int_overlap -- does a overlap b?
 */
Datum
_int_overlap(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    ArrayType  *b = PG_GETARG_ARRAYTYPE_P_COPY(1);
    bool        result;

    CHECKARRVALID(a);
    CHECKARRVALID(b);
    if (ARRISEMPTY(a) || ARRISEMPTY(b))
        return FALSE;

    SORT(a);
    SORT(b);

    result = inner_int_overlap(a, b);

    pfree(a);
    pfree(b);

    PG_RETURN_BOOL(result);
}

Datum
_int_union(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    ArrayType  *b = PG_GETARG_ARRAYTYPE_P_COPY(1);
    ArrayType  *result;

    CHECKARRVALID(a);
    CHECKARRVALID(b);

    SORT(a);
    SORT(b);

    result = inner_int_union(a, b);

    pfree(a);
    pfree(b);

    PG_RETURN_POINTER(result);
}

Datum
_int_inter(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    ArrayType  *b = PG_GETARG_ARRAYTYPE_P_COPY(1);
    ArrayType  *result;

    CHECKARRVALID(a);
    CHECKARRVALID(b);

    SORT(a);
    SORT(b);

    result = inner_int_inter(a, b);

    pfree(a);
    pfree(b);

    PG_RETURN_POINTER(result);
}


PG_FUNCTION_INFO_V1(intset);
PG_FUNCTION_INFO_V1(icount);
PG_FUNCTION_INFO_V1(sort);
PG_FUNCTION_INFO_V1(sort_asc);
PG_FUNCTION_INFO_V1(sort_desc);
PG_FUNCTION_INFO_V1(uniq);
PG_FUNCTION_INFO_V1(idx);
PG_FUNCTION_INFO_V1(subarray);
PG_FUNCTION_INFO_V1(intarray_push_elem);
PG_FUNCTION_INFO_V1(intarray_push_array);
PG_FUNCTION_INFO_V1(intarray_del_elem);
PG_FUNCTION_INFO_V1(intset_union_elem);
PG_FUNCTION_INFO_V1(intset_subtract);

Datum
intset(PG_FUNCTION_ARGS)
{
    PG_RETURN_POINTER(int_to_intset(PG_GETARG_INT32(0)));
}

Datum
icount(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
    int32        count = ARRNELEMS(a);

    PG_FREE_IF_COPY(a, 0);
    PG_RETURN_INT32(count);
}

Datum
sort(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    text       *dirstr = (fcinfo->nargs == 2) ? PG_GETARG_TEXT_PP(1) : NULL;
    int32        dc = (dirstr) ? VARSIZE_ANY_EXHDR(dirstr) : 0;
    char       *d = (dirstr) ? VARDATA_ANY(dirstr) : NULL;
    int            dir = -1;

    CHECKARRVALID(a);
    if (ARRNELEMS(a) < 2)
        PG_RETURN_POINTER(a);

    if (dirstr == NULL || (dc == 3
                           && (d[0] == 'A' || d[0] == 'a')
                           && (d[1] == 'S' || d[1] == 's')
                           && (d[2] == 'C' || d[2] == 'c')))
        dir = 1;
    else if (dc == 4
             && (d[0] == 'D' || d[0] == 'd')
             && (d[1] == 'E' || d[1] == 'e')
             && (d[2] == 'S' || d[2] == 's')
             && (d[3] == 'C' || d[3] == 'c'))
        dir = 0;
    if (dir == -1)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("second parameter must be \"ASC\" or \"DESC\"")));
    QSORT(a, dir);
    PG_RETURN_POINTER(a);
}

Datum
sort_asc(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);

    CHECKARRVALID(a);
    QSORT(a, 1);
    PG_RETURN_POINTER(a);
}

Datum
sort_desc(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);

    CHECKARRVALID(a);
    QSORT(a, 0);
    PG_RETURN_POINTER(a);
}

Datum
uniq(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);

    CHECKARRVALID(a);
    if (ARRNELEMS(a) < 2)
        PG_RETURN_POINTER(a);
    a = _int_unique(a);
    PG_RETURN_POINTER(a);
}

Datum
idx(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
    int32        result;

    CHECKARRVALID(a);
    result = ARRNELEMS(a);
    if (result)
        result = intarray_match_first(a, PG_GETARG_INT32(1));
    PG_FREE_IF_COPY(a, 0);
    PG_RETURN_INT32(result);
}

Datum
subarray(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
    int32        start = PG_GETARG_INT32(1);
    int32        len = (fcinfo->nargs == 3) ? PG_GETARG_INT32(2) : 0;
    int32        end = 0;
    int32        c;
    ArrayType  *result;

    start = (start > 0) ? start - 1 : start;

    CHECKARRVALID(a);
    if (ARRISEMPTY(a))
    {
        PG_FREE_IF_COPY(a, 0);
        PG_RETURN_POINTER(new_intArrayType(0));
    }

    c = ARRNELEMS(a);

    if (start < 0)
        start = c + start;

    if (len < 0)
        end = c + len;
    else if (len == 0)
        end = c;
    else
        end = start + len;

    if (end > c)
        end = c;

    if (start < 0)
        start = 0;

    if (start >= end || end <= 0)
    {
        PG_FREE_IF_COPY(a, 0);
        PG_RETURN_POINTER(new_intArrayType(0));
    }

    result = new_intArrayType(end - start);
    if (end - start > 0)
        memcpy(ARRPTR(result), ARRPTR(a) + start, (end - start) * sizeof(int32));
    PG_FREE_IF_COPY(a, 0);
    PG_RETURN_POINTER(result);
}

Datum
intarray_push_elem(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
    ArrayType  *result;

    result = intarray_add_elem(a, PG_GETARG_INT32(1));
    PG_FREE_IF_COPY(a, 0);
    PG_RETURN_POINTER(result);
}

Datum
intarray_push_array(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
    ArrayType  *b = PG_GETARG_ARRAYTYPE_P(1);
    ArrayType  *result;

    result = intarray_concat_arrays(a, b);
    PG_FREE_IF_COPY(a, 0);
    PG_FREE_IF_COPY(b, 1);
    PG_RETURN_POINTER(result);
}

Datum
intarray_del_elem(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    int32        elem = PG_GETARG_INT32(1);
    int32        c;
    int32       *aa;
    int32        n = 0,
                i;

    CHECKARRVALID(a);
    if (!ARRISEMPTY(a))
    {
        c = ARRNELEMS(a);
        aa = ARRPTR(a);
        for (i = 0; i < c; i++)
        {
            if (aa[i] != elem)
            {
                if (i > n)
                    aa[n++] = aa[i];
                else
                    n++;
            }
        }
        a = resize_intArrayType(a, n);
    }
    PG_RETURN_POINTER(a);
}

Datum
intset_union_elem(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P(0);
    ArrayType  *result;

    result = intarray_add_elem(a, PG_GETARG_INT32(1));
    PG_FREE_IF_COPY(a, 0);
    QSORT(result, 1);
    PG_RETURN_POINTER(_int_unique(result));
}

Datum
intset_subtract(PG_FUNCTION_ARGS)
{
    ArrayType  *a = PG_GETARG_ARRAYTYPE_P_COPY(0);
    ArrayType  *b = PG_GETARG_ARRAYTYPE_P_COPY(1);
    ArrayType  *result;
    int32        ca;
    int32        cb;
    int32       *aa,
               *bb,
               *r;
    int32        n = 0,
                i = 0,
                k = 0;

    CHECKARRVALID(a);
    CHECKARRVALID(b);

    QSORT(a, 1);
    a = _int_unique(a);
    ca = ARRNELEMS(a);
    QSORT(b, 1);
    b = _int_unique(b);
    cb = ARRNELEMS(b);
    result = new_intArrayType(ca);
    aa = ARRPTR(a);
    bb = ARRPTR(b);
    r = ARRPTR(result);
    while (i < ca)
    {
        if (k == cb || aa[i] < bb[k])
            r[n++] = aa[i++];
        else if (aa[i] == bb[k])
        {
            i++;
            k++;
        }
        else
            k++;
    }
    result = resize_intArrayType(result, n);
    pfree(a);
    pfree(b);
    PG_RETURN_POINTER(result);
}
